Question

I am looking for an open source library to parse and execute formula/functions in C#.

I would like to create a bunch of objects that derive from an interface (i.e. IFormulaEntity) which would have properties/methods/values and the allow a user to specify formulas for those objects.

For example, I might have

public class Employee : IForumulaEntity
{ 
      public double Salary { get; set; }
      public void SendMessage(string message)
}

Then allow an application user to write something like;

Employee person = <get from datasource>
if (person.Salary > 1000)
    person.Salary += 1000;

person.SendMessage("Hello");

This “looks like C#” but it would be a simplified programming language. I know it’s alot to ask. I would expect my users to be reasonably capable (i.e. can write their own Excel formulas).

Answer 1

Look into the Rules Engine functionality that is part of Windows Workflow Foundation.

This is not a place one would think to look. However, as part of the work they did to produce a UI that allows a Workflow developer to use configurable rules and expressions, they’ve come up with a way to do the same thing in your own application, even if you are not using Workflow at all. Their documentation includes examples of hosting this functionality in a Windows Forms application.